The movie "Winchester '73" follows a valuable rifle as it passes through the hands of more than two dozen people until finally it lands with its rightful owner. The story is a fascinating look into how different the motivations of gun owners are. Even legally purchased guns have curious and sometimes violent histories. Because laws have created a framework for how guns are claimed and who can purchase them, it is easier now to find their histories. Many gun owners explore the history of their guns as a hobby. Also, knowing the gun's history relieves other owners, who might have concerns about previous users.
Narrow down the possibilities for dates of ownership by getting the model information from the gunmaker. Each model is available for about a decade, and many gun features change many times through the run of a model. If the gunmaker is out of business, check public records and relevant works. For instance, though the manufacturer Winchester is defunct, one place to lookf or more detailed information is Dean K. Boorman's "History of Winchester Firearms."
Register the gun as soon as possible. As part of the registration process, the local police department will often run the serial number to find out previous owners. If the gun has been registered to each owner, the history will emerge. A lack of registered history, of course, does not mean it didn't have other owners.
Ask the seller of the gun about its known history. If you bought the gun privately, the history might be mostly undocumented. The previous owner might be able to give a lead. Be skeptical of apocryphal, exaggerated or secondhand stories. Follow up on any leads that you get, such as states it has passed through. Some states such as Florida have searchable databases of registered guns where you can further explore the information the salesman gives you.
Request a search by the state or by the Bureau of Alcohol, Tobacco, Firearms and Explosives if local law enforcement cannot find its history. The ATF is responsible for regulating the sale of firearms between states and preventing the illegal manufacturing of weapons.
Consult a historian or antique gun dealer if the gun is more than 50 years old. Some university specialists study guns, as well as online dealers such as Merz Antique Firearms. Most of the history will probably be irrecoverable, but you can find out which period it's from and which uses it was put to.